Which programme of the Government of India directly targets at improving sex-ratio?

The correct option is Beti Bachao Beti Padhao.

Explanation:

Beti Bachao Beti Padhao (BBBP) (translation: Save the Girl Child, Educate the Girl Child) is a campaign of the Government of India that aims to generate awareness and improve the efficiency of welfare services intended for girls. The scheme was launched on 22 January 2015 by Prime Minister Narendra Modi to address the issue of the declining child sex ratio (CSR) image and related issues of women empowerment over a life-cycle continuum.

Let's look at why the other options are not the primary direct answers:

1. Widow Pension: This is a social security scheme aimed at providing financial assistance to widows, rather than addressing the birth sex ratio directly.
2. Pre-Natal Diagnostic Techniques (PNDT) Act: While this is a legislative act passed to prohibit prenatal sex determination and prevent female foeticide, it is a legal regulation rather than a social welfare or development programme directly targeting multi-sectoral action.
3. Sukanya Samriddhi Yojana: This is a small savings scheme targeted at the parents of girl children, encouraging them to build a fund for the future education and marriage expenses of their female child.